Magnetic ore-separator.



.NG. 832,828. PATENTED 0018; 1906. H. H. WAIT.

MAGNETIC ORE SBPARATOR. APPLICATION FILED MAR. 20, 1906.

2 SHEETS-SHEET l.

Z6Q/Z7Z6 656-5 Z72 ae/zfarx fkaz' UNITE STATES P iETENT ()FFICE.

HENRY H. WAIT, OF CHICAGO, ILLINOIS, AssIGNOR TO INTERNATIONAL SEPARATOR COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF NEW JERSEY.

MAGNETIC QR -SE RAT'QR.

Specification of Letters Patent.

Patented Oct. 9, 1906.

Application filed March l 1905. Serial No. I,Q77-

To all whom it may concern.-

Be it known that I, HENRY H. WAIT, a citizen ofthe United States, residing at Chicago, in the county of Cook and 'State of Illi- IlOlS, have invented a certain new and useful Improvement in Magnetic Ore-Separators, of which the following is afull, clear, concise, and exact description.

My invention relates to a magnetic separator; and its object is to provide an im proved construction of the parts adjacent to the separating-gap such that an effective separation and divlsion of the magnetic materialfrom that which is non-magnetiocan be accomplished with the minimum expenditure of energy 'and'with the least possible liabilit of either the magnetic or non-magnetic pro 'uct containing any considerable percentage of the other. In other words, the object is to obtain as clean a concentrate as ossible. My invention relates generally to t at type of magnetic separator in which the material to be treated is passed between the surface of a revolving drum or armature and a magnetpole facing the same; and the invention resides particularly in the shaping of the polepiece with reference to the armature, the 10* cation of the divider-plate, and the provision of a non-magnetic screen for the pole-piece so shaped and placed with reference to the divider-plate and pole-piece as to produce the most effective separation of the magnetic and non-magnetic particles.

binations which I regard as novel will be;

pointed out in the appended claims.

Figure 1 is a view' in elevation and half in section of an ore-separator constructed in accordance with my invention. Fi 2 is a detail view showing the manner in which the surface of the armature is built u a sectional detail, on an enlarge scale, illustrating the parts at the Working gap of the machine, showing approximate directions of the lines of force. "Fig; 4 is a similar sectional detail showing the paths taken by the different kinds of ore particles at the place of separation. I

In the magnetic attraction of a particle, the

movement is always in the direction of an in Fig. 3 is the lines of force. Magnetic ore-separators have been constructed to utilize this principle by providingpermeable projections or mag- In general the attraction is along netic teeth upon the surface of a revolving,

armature and passing the material to be separated between these rojections and a magnetic poleiece, the i ea being that the more magnetica lyzpermeableparticles in the mix-- rawn alongconvergin lines of ture will be. force to the teeth or projections on t e armature rather than to the surface of the polepiece.

In Fig. 1 an ore-separator working on this plan is illustrated. The armature c is mounted to rotate between opposing polepieces N and S. A receiving-hopgier f is pro vided from which the material is ed through the spout g and through suitable feed-controlling mechanism to the upper surface of the rotating armature, said material being carried around in the rotation of said armature past the pole-piece N, at which separation takes place. A divider p is provided underneath the armature with its edge ex-,

tending up toward the working air-gap, and the magnetic material attracted to the surface of the armature is carried past the edge of the divider and falls on one side thereof, se aration thus being effected.

in the machine illustrated the armature is composed of laminatedplates d d, assembled upon the shaft b, and the plates are provided with teeth or serrations e e at their peripheries, the plates being assembled in relative positions to present the teeth in. staggered rows upon the surface of the armature. Mag-' netizing-coils mm are provided u on the op posin ole-pieces N S of the fiel' -magnet to establish across the air-gaps. The flux through one of these air-gaps is utilized for the purpose of separation, while the other pole-piece on the opposite side of the armature is for the purpose of balancing the magnetic pull, so that the armature may turn in its bearings with the least possible amount of friction.

In the machine illustrated the divider p is shown mounted upon a rocking shaft 1:,

a magnetic flux between said polepieces and the armaturethat is to say;

" fromit toward the lower edge of thepolewhich may be adjusted by the mechanism shown to vary the position of the edge of the divider-plate according to the strength of the field and the material being treated.

Coming now to a articular description of the novel features of this invention, and re ferring first to Fig. 1, it will be seen that a shield a is provided over the face of the magnet-pole N, this shield being curved upwardly toward the surface of ,the armature instead of being concentric therewith. The pole-piece is cut away at the top, as shown in 'ig. 1, so as to produce a concentration of the =field' just 'below the horizontal axis of the armature. The shield at is close to the armature at the top,- but gradually curves away face, so as to allow a gradually-increasing s ace between said armature and said shield.

y reference to 3 it will'b-e seen that the magnetic 'linesof-force diverge from the teeth ofthe armature toward the pole-piece N, and the shield-plate in front of the. pole-face prevents the ore articles from comilng into any position in w hioh the lines of'force will converge toward the pole-piece N- instead of toward the armature, It will be seen that v the shield a is close against the faceof the ward the teeth on-thearmature rather than.

toward-the pole-face.

magnetipole at the lower edge, but gradually curves upward away from the pole-face and toward the'armature, so that orearticles near the top are held by the shie d much closer to the surface of the armature than they could st to the surface of the polepiece. In ot erwords, the shield is so-located that the-density of the magnetic flux at all places in the working gap will increase to- They gradual increase in the width of the working gap between the armature-surface and the shield a permits the sheet of ore to gradually fan out in-pa'ssing through the in tense portion of the field. In other Words,

the opening of the-working gap is constricted near'thetopto take only a certain quantity of-mater1al;'but toward'thedenser portion of the field the space is increasedto permit the magnetic articles-to separate out more readily-from t e non-magnetic material.

Fig. 4 showsmore clearly the arrangement and curvature ofthe pole-piece and the shieldv with reference to theother parts.

plate and the location of the divider plate The polepiece is arranged to roduce'the most intense magnetic action of-t e ore-particles near the lower edge. The location of the divider plate is determined as follows: Non-magnetic particles passing over the armature Willfall' outside of a line X tangent to the-toothedsurface of the armature, f and the dividerplate-will therefore be located somewhere-inside of this line X. There must be room for attracted material adhering to 'the surface of the armature to pass beyond the edge of the divider plate. Assuming the lar est size particle to be treated, the curved line K is illustrated to bound the space which would necessarily be required by such a article if it were held tightly against the sur ace of the armature; but in many cases the magnetic particle which has been attracted to the armature will be released assoon as it leaves the densest portion of the field near the lower edge of the working gap, Disregarding the effect of gravity, therefore, the attracted particle released from the surface ofthe armature at the point where the magnetic action begins to decrease will followaa leasta path tangent to the armature, so that the edge of the divider-plate must beoutside of this line, (indicated by the line Z.) The actual trajectory of the fallin ,magnetic -particle,however, will be slight ymore vertical, due tothe action of gravity, and the path of the outer edge ofsuch-a magnetic particle of maximum size released from the-armature, at the point wherethemagneticfieldfirst-beginstodecrease in strength will be indicated by the line Y.

The lines X and Y, therefore, form the inner and outer limits of the space within which the divider-plate should properly be placed, andif there were no interference between the moving particles the edge of the dividerplate might be located close up in the angle of these lines Y and X. ,As'it is usually desirable to feed a considerable volume of ore into the separator, the interference betweenthe particles fans out the stream of ore, so that the divider-plate cannot in practice come quite-up to the'limits referred to, but willbelocated slightlvinside of these limits, as shown in Fig. 4.

The shield-plate a should be so curved that non-magnetic articles-thrown off the armature by centri ugal force against said shield and rebounding therefrom will always fall outside of the divider-plate and not be mingled with the magnetic material. In Fig. 4a curvature of the shield late ais illustrated, such that particles fal ing off tangentially from the armature at any point above the horizontal axis and striking the shield-plate will be given such an an le of-rebound or d8? fiection that they will a ways falloutside of the divider-plate. This curvature is determined by the location of the divider-plate and the tangential trajectories of particles thrown off from the armature-surface, the surface of the shield-plate bcing'such as to form equal angles of incidence and deflection with the tangential lines of trajectory T and the lines L from a point outside of the edge of the divider-plate to the point wherethe particles-strike-t-he shield-plate. Preferably the shield-plate a-is-rnade of non-ma netic material, such as brass; but it is possi Is to secure flux, and therefore does not exert a very considerable influence on the directions of the lines of force.

I claim 1. In a magnetic separator, the combina tion with a rotating carrier having permeable pole-piece and carrier along a short arc just elow the horizontal axis, a shield over the face of the pole-piece, said shield being curved upwardly away from said pole-face, and means for passing-material to bezse arated between saidcarrier and said shiei shield being located and shaped to provide a Working gap in which the density of the magnetic flux shall increase toward the permeable projections on the carrier, whereby the magnetic particles are prevented from being drawn toward the ole-piece, and a dividerplate extendin to the most concentrated portion of the fiel 2. In a magnetic separator, the combination with a rotating armature having means for causing divergences of the magneticflux from its periphery, of a magnet pole-piece facing said armature and pro ecting'close to the periphery thereof along a shortarc below the horizontal axis of said armature, the lower portion of the poleiece approaching closer to the armature t an the upper portion thereof, a shield over the face of the polepiece, means for passing material to be separated through the working gap between said shield and said armature, said shield being curved gradually away from the pole-piece and toward the surface of the armature at the top to form a restricted opening through which the ore may be passed, the working passage between said shield and said armature being gradually increased in width toward its lower end, substantially as and for the purpose set forth.

3. In a magnetic separator, the combination with a rotating cylindrical armature having magnetic teeth'at its periphery, of a polepiece facing said armature, a non-magnetic shield over the face of said pole-piece, said shield being gradually curved away from said (1, said pole upwardly toward the surface of said armature, thereby forming a working gap between said shield and armature of graduallyincreasing width toward. the lower end, the space between said shield and pole-piece being of gradually-decreasin width toward the same end; whereby a wor ing gap is formed in which the density of the magnetic flux at all laces therein will increase toward the teetli on the armature and not away from the pole-face.

4. In a magnetic separator, the combination with a horizontal rotating cylindrical armature having means for causing dispersions of the ma netic flux at its. eriphery, of a magnet po e-piece facing said armature and closely approaching thereto alon an are just below the plane of the horizonta axis thereof, the lower portion of said pole-piece approaching the armature more closely than the upper portion thereof, a thin shield for said pole-piece extending upwardly around the armature-surface, said shield being curved away fromsaid pole-piece and gradually approaching the armature toward the top to form a working gap between said armature and said shield gradually increasing in width downwardly, and a divider-plate on the-under side of said armature, said shield being given a curvature adapted to reflect particles thrown againstv said shield by said armature at such an an le that said particles will fall outside of the (lIVldBP-Pltlt whereby non-magnetic material is prevented from rebounding into the magnet1c concentrate.

5. In a magnetic separator, the combination with a horizontal revolving cylindrical armature having means for causing dispersions of the ma netic flux at its periphery, of

a magnet-pole facing one side of said arma-.

ture, a shield over the face of said pole-piece, said shield being curved gradually away from said pole upwardly toward the surface of said armature, and a divider-plate extending to the most concentrated portion of the field, said shield being given a curvature at its lower end adapted to deflect impinging particles outside of said divider-plate.

In witness whereof I hereunto subscribe my name this 13th day of March, A. D. 1905.

"HENRY H. WAIT. Witnesses:

IRVING MACDONALD,

DE Wrr'r C. TANNER. 

